Gene expression profiling indicates inflammatory pathways involved in IUGR due to placental insufficiency

Intrauterine growth restriction (IUGR) represents a major obstetric challenge with perinatal complications and a risk factor of developing disease in adult life. Placental insufficiency is one of the common features accompanying IUGR. The aim of this study was to evaluate global placental gene expression profile in IUGR compared to normal pregnancies. Placental samples were collected by eight IUGR pregnancies with placental insufficiency ascertained by Doppler and eight healthy controls. A 30K Human Genome Survey Microarray v.2.0 (Applied Biosystems) was used to evaluate global gene expression profile. Principal component analysis showed good separation in terms of gene expression patterns between the groups. Pathway analysis with Bonferroni correction for multiple testing showed significant (p<0.05) up-regulation of inflammation mediated by chemokine and cytokine signalling pathway in the IUGR placentas. Genes involved in metabolism of glucocorticoids (HSD11B1 and DHRS2) were found differentially expressed. We found no imprinted genes to be differentially expressed and only one gene involved in epigenetic modifications (MBD3) to be down-regulated in the IUGR placentas, indicating that IUGR due to placental insufficiency is not associated to placental imprinting. Subgroup analysis between pure IUGR and IUGR with preeclampsia placentas showed only 27 differentially expressed genes suggesting common pathophysiology. Eight placental samples from normal human placenta compared to eight human placental samples from patients with intrauterine growth restrictions due to placental insufficiency